Process for the production of glucose from materials containing cellulose



Patented Sept. 6, 1927.

UNITED STATES LUDOLF MEILER ANDHEINBICH SOEOLLER, OF MUNICH, P

CELL'ULOSE.

raocnss run run rnonucrron or GLUCOSE rnou mrnnms con'rnmntc 30 Drawing. Application filed September 10, 1924,

7 Our invention relates to the production of glucose from materials. containing cellulose and refers particularly to the production of crystallized glucose from wood and other materials containing non-cellulose matters.

The production of glucose from wood is known, but these processes have been found to be incapable oicommercial adoption be- 10 cause of the difiiculties incident to the steps of production.

1n the known processes for the production of glucose from Wood, and similar substances, a considerable amount of non-cellulose material is dissolved, preventing the crystallization of the glucose and hence'resulting in impure final products.

Further, in the known processes, theintermediate products are produced in. a form which is extremely difficult to filter and as during this process of filtration the dextrine is partly decomposed into Water soluble compounds, the processes present dificulties which prevent their commercial application.

We havelovercome the above and other ditficulties and objections incident to the present known processes, our process presenting a means for the production of crystallized glucose from impure cellulose ma-.

terialsin an economical, efiicient and commercially practical manner. We have found that, if impure cellulose materials, such as Wood, be moistened with a mineral acid and then submitted to the action of acid gas under pressure at low temperatures, there is produced a solution of cellulose. The solution of cellulose thus produced is diflicult to filter from the in- 2 soluble non-cellulose materials in the condition thus formed, the length of time necessary for such filtration resulting in the production of objectionable water-soluble dextrine products, interferring with. the production of pure glucose and contaminating Serial No. 736,920, and in Germany mm as, 1921.

thus obtained may be converted into glu-.

cose by weak acid, this saccharification being. produced by acid very considerably weaker than that necessaryfor the conversion of starch into glucose.

It will thus be seen that the process of our invention comprises new methods for the production of glucose from impure cellulose materials and that it overcomes many objectionable features incident to the pre viously known methods and that our processallows of the production of glucose from materials not previously of practical application for that purpose I As it is desirable to produce a concentrated solution of cellulose, we prefer to moisten the impure cellulose material, as, for instance, wood, with concentrated hydrochloric acid and then treat it with hydro chloric acid as under action of the hy rochloric aci gas increases the dissolving efiject of the acid, which takes place at low temperatures. In the. follow 'ing of our procem, we prefer that the temperature at this point should not exceed 10 6., as higher temperatures cause a decomposition of the cellulose with the formation of water soluble compounds, resulting in decreased yields. For this reason, we also prefer to employ cooled h drochloric acid, in order to prevent an un esirable increase in tem rature. We prefer to have a pressure 0 about ,4 atmosphere, although this pressure may be increased if strong agitaressure. The

lid

tion is employed during the dissolving process. 7

At the end of this step of our process, the greater part of the non-cellulose material is undissolved and is in suspension in the solution.

It is extremely dificult to separate the non-cellulose materials from the dissolved substancesaind, during the long filtering o eration, the dextrine is decomposed into 0 jectionable water-soluble materials. We convert this mixture, whichis cult to filter,

sponding reduction in the production ofundesirable dextrine decompositions, by reducing its concentration by the addition of 'wa-- being allowed to exceed 10 C.

ter, ordilute hydrochloric acid, without precipitatin'g the dissolved compounds. We find that the reduction of concentratlon .to about 30% acid is usuallyeflective'.

The soluble matters are now filtered from the insoluble ones and the filtrate...diluta(LQ6ll11 Q- by water, or weak acid, causing a precipitation of the glucose producing bo ms, or the cellulose dextrines. i

The cellulose dextrines are now freed from acid as far as possible, which is usually possible toa 0.1% acid content and a 20% suspension of'the cellulose dextrme 1S employed .for saccharification.

We have found that this dextrine can be saccharified with an unexpected wealrsolution of hydrochloric acid, which is much weaker than'that necessary in the conversion of starch into glucose. F orthis saccharification we have employed an acid concentration of 0.1% and have obtained a yield of 80% in 30 minutes at a temperature of 170 C. a

The solution is then filtered, dE'CQlOI'lZGd neutralized with soda-ash, concentrated and crystallized. I

- As an example of our process, following: a

One part of dry sawdust is moistened with two arts of cooled concentrated hydrochloilc acid. Hydrochloric acid gas is then passed into the well stirred mixture at 4 atmosphere pressure, the temperature not When 7 v viscous mass has been converted into a thin suspension, which usually occurs in about 20 minutes, the suspension is diluted with water, or weak hydrochloric acid, without precipitation and filtered. The filtrate is diluted with an e ual quantity of water, whereupon thecel ulose dextrine precipitates. The dextrine .is se arated as comletely as possible from t e acid and di-' liited with water to produce a 20% suspension." The content of h drochloric acid is reduced to 0.1% by washing and the mixture heated for 30 minutes to 170 C. The produced glucose solution is filtered, de-

we give the 'colorized, concentrated and crystallized.

We do not limit ourselves to the particular chemicals, quantities, times, tempera;- tures, pressures, or steps of procedure mentioned above, as these are given simp y to clearly describe the process of our invention.

What we claim is:

1. The process of producing glucose from cellulose-containing material, which comprises treating the material with a mineral acid, treating the resulting mixture to the influence of mineral acid gas under pressure, diluting the resulting mixture without precipitation, separatin the undissolved materials from the solub e ones, solution causin a precipitation, separating the precipitate; materials from the solution, treating the precipitated materials to form glucose and separating the glucose from the solution. v

2. The process of producing glucose from containing material, which. comprises treatihg the materiahwith hydro-*" chloric acid,--submitting the resulting mixture to the action of hydrochloric acid gasthe resulting mix under pressure, diluting ture without causing a precipitation, filtering the insoluble matters from the soluble ones, diluting the filtrate causing the formation of a precipitate, filtering the, mixture, saccharificating the filtered precipitate form- V. in'g glucose and recovering the glucose from the solution. 7

3. The process of producing glucose from wood, which comprises treating the wood with strong mineral acid, subjecting the resulting products to the action ot'the mineral acid gas under pressure, diluting the resulting mixture without forming a pro diluting the cipitate, filtering, dilutingthe filtrat-e form ing a precipitate, filtering, sacoharifying the resldue forming glucose and recovering the glucose from the solution.

4:. The process of producing glucose from cellulose-containing material, which comprises treating the material with hydrochloric acid, submitting-the resulting mixture to the action of hydrochloric acid gas under pressure at not exceeding 10 ture, diluting the resulting mixture without "causing a precipitation, filtering the insoluhle matters from the soluble ones, diluting the filtrate causing the formation of a prcipitate, filtering the mixture, saccharificat ing the filtered precipitate forming glucose and recoveringthe glucose from the solution.

5. The process of producing glucose from cellulose-containing "material, which comfrom cellulose-containing material, the steps which comprise treating the material with a mineral acid andthen treating the result ing mixture with a mineral acid gas under pressure forming a concentrated solution of cellulose without the formation of appre- G. tempera=- under ressure forming c concentre sou tion 'CGlllllOSfi without the formation of appreciable qusntitiw of water-soluble lose decomposition prouucts.

' from cellulose-contag materiel, the

8. In the process of produc glu 1w.-

W which comprise treatiu the materiel with hydIOOhIOIIO acid and tlzen treeting the are suiting mixture with hydrochloric was gas under pressure at e temperature not exceed.- ing 10 C. forming e conceutreted solution of cellulose.

9. In the process of priming glucose from cellulose-containing materiel the steps which comprise producing e solution of cellulose end uilutmg the solution of without the formation of appreciable queu tities of water-soluble ceulcse e tiori pucts without w. preciitetea 10. the process of rm? 1 from celluloseweuteint; metericl, the ste whichcomprise producing err acid solution of cellulose containing non-soluble matters, ti luting the mixture without formin e pre-= cipitate and separating the nou-solule mut-= ters' from the soluble matters.

11., from cellulose-containing material, the etc which com rise convertin the cellulose into water-preclpitatuhle cellu ose d'extriue end seccherifying the dextrine.

12. In the process of producing ms: from cellulose-coutaiuiu material the which comprise converting thecellulose into weter-preci pitstchle cellulose dextre end seccherifymg the dextriue by, m of week acid. I

Sied at which; Germany, this y of August, 1924. v

LUDOLF 'sil. ll

the process ofproducing glucca 

